Switch box latch with variable bias



March 1956 D. w. JOHNSON SWITCH'BOX LATCH WITH VARIABLE BIAS Filed April'7, 1953 E6 19 IYU/rLZO-m Y DaA/cdnilfo 71.116011 g ILQEEEOYI SWITCH BOXLATCH WITH VARIABLE BIAS David W. Johnson, Newington, Conm, assignor toThe Arrow-Hart & Heg man Electric Company, Ha tford, 30 1 a orporationof C nn c c t.

Application April 7, 1953, Serial No. 347,301

13 Claims. (CL 292-24) This nvention r l tes to duplex la che f r x cvers andv more particularly to electric switch box covers or doors inthe larger sizes. The invention is not limited. howevfir to anyparticular box size or to electric switch boxes. The invention isparticularly Useful in connection metallic boxes in order to comply withUnderwriters les a for other re son n m ny instance er must be provisionof an interlock so that the box cover will remain shut When the switchhandle is in the closed circuit position. The interlocking arrangementreferred to is dependent upon the position of the handle and s t h; andi s d na y nsid he box or un a lable for manual manipulation from theoutside except by the use of a special tool or screwdriver. It is thusimpossible for anyone to open the cover while the switch is in closedcircuit position. Beside the provision of mechanism for accomplishingthe aforementioned functions, there is sometimes provided a thirdposition of, the handle. different from both the on and oil positionsand into which the handle must be moved and held betorethehandle-controlled latching means is disabled and opening of the cover ispermitted. Obviously when there is a provision for this third momentaryposition, one hand of the operator must be occupied in holding thehandle. in said position.

In addition to the foregoing, it is desired and of en required that thebox cover have additional latching means, independent of the switch, tooperate automatically when the cover closes. To that end, latching meansis provided on the exterior of the box body to cooperate with means onthe cover to snap into operative latching position when the covercloses.

In thelarger size of switch boxes, the provision of one. such exteriorlatch is insufiicient for various reasons and to obtain unauthorized orimproper access to the interior. To. avoid that possibility, more thanone latch is provided. It is obvious however that if such latchesarespring biased so as to automatically move to closed position when thecover closes, difiiculty will be encountered in trying to hold thehandle of the switch the box opening position and at the same time toovercome the spring bias of the exterior latches. Indeed it is quiteimpossible to do so without at first moving one of the latches into openposition and prying it there and then holding the other latch with onehand while the switch handle is held in the proper box opening positionwith the other hand. The invention is not limited to use of two latches,together. In some instances only one latch may be used and many of theadvantages of the invention will he put to use.

With these problems in mind, it is an object of the present invention toprovide a spring biased exterior latch- United States Patent 2,739,002Patented Mar. 20, 1956,

ing means for switch box covers and the like in which the latch may beeasily adjusted to be retained in position permitting opening of the boxwithout the need to use special means or tools.

Another object of the invention is to provide such a latching means thatis economical to manufacture and assemble and may be easily fabricatedmainly from sheet metal stampings. I

Another object of the inventionis to provide latching means of theaforementioned type in which the exterior latch may be biased toautomatically engage its .keepe'r or not to engage its keeper, by merechange of the position of the biasingispring manually without the needfor use of tools or other special means.'

A related object is to provide such alatching means which will permitsecuring together of the box and cover by a screw with the latchingmeans biased in either of its two positions.

Otherobjects and advantages of the invention will become apparent as theinvention is described in connection with the accompanying drawing:

In the drawing: I

Fig. l is aside'elevation view of a box to which the invention isapplied wherein the'top latch is biased open and the bottom latch isbiased closed. Fig. 2 is a front elevation view of the box and top latchof Fig. 1. Fig. 3 is a view looking up at the structure of the bottomlatch assembly of Fig. 1. Fig. 4 is a detail side view of one of themovable latch members.

Referring to the drawings, a rectangular sheet metal switch boX 10 has astamped sheet metal door or cover 12 hingedly mounted thereon with aperipheral flange on the door overlapping the sides of the box. On thedoor 12 is pivotally mounted a switch operating handle or lever 14 ofany suitable or conventional form. For the purpose of description andbetter understanding of the invention, it will be assumed that thehandle is capable of occupying at least an 'on and Off Position and an11cm po i wh ch. op n. position the handle must be moved before thecover can be opened. Since many possible means for interlocking thecover and the box when the handle is in any position except the. fop n pition. m y e i rporat no sp cific means needbe described andillustrated. It need only be mentioned that the interlocking arrangementbetween the handle, cover and box is entirely enclosed Within the boxand can only be rendered ineffective by movement of the handle into saidopen position.

Other means independent of the position of the handle are provided sothat the cover may be latched to the box when the cover is closed. Theseadditional means consist of identical latching devices, one beinglocated preferably near the top of the box at the side thereof while theother is located near the bottom, Mounted on the side flange of the door12 of the box at spaced points near the top and bottom are weldedstamped sheet metal angle brackets. One arm 16 of the angle is welded tothe cover so that the other arm l7 will extend ne pendie lar-ly theretoparalleling the cover of the box, The eyes:

tending arm 17' thus constitutes the keeper of the latch device.

Mounted upon the box at the sidethereof adjacent the.

location of the keeper lugs is a two-part latching assembly. Thisassembly on the box comprises a mounting bracket, designated generallyby the numeral 20, stamped frorn'sheet metal and welded'to the side ofthe box 10,, The bracket has an L-shaped mid-portion with one arm 22torming a mounting portion welded to the box and the other arm 21 ofisetby'an amount slightly greater than the thickness of the metal. At theend Of arm 21 a wing 26 is bent outwardly at right angles to the planeof the side of the box and parallel to the plane of the cover, the wingis pierced and threaded to receive a screw bolt 19. It may also have asecond circular piercing 27 in a depending extension of the wing, toreceive the loop of a padlock P. t

The top end 23 of arm 22 is bent outwardly at right angles to the planeof the side of the box and at right angles to the plane of the cover andhas a narrow rectangular slot 24 cut in the edge farthest from the coverproviding a bearing recess for the movable latch member 30.

The movable latch, designated generally by numeral 30, is stamped fromsheet metal preferably but not necessarily of the same gauge as thebracket 20. The movable latch 30 has formed at one end of its body ahook-like formation 31 providing a bearing toengage in the bearingrecess 24 of the bracket 20. On the other end of the latch body isformed a latch nose 32 adapted to engage the keeper 17 on the door orcover.

The latch body is extended down at its central portion and offset towardthe box as at 33, then continuing along the surface of the side of thebox parallel thereto and to the plane of the upper portion of said body.Bent out at right angles to the lower portion 34 perpendicular to theside wall of the box and adapted to parallel the bracket wing 26 is alatch wing 35 into which is stamped a keyhole-shaped aperture 37. Freelythrough the keyhole slot extends the securing screw bolt 19. Ontightening up the bolt, the latch 30 pivots into latching position andthe latch wing 35 is screwed tight against the bracket wing 26, thussecuring the cover closed permanently without regard to the condition ofthe apparatus in the box.

In order to enable opening of the box while one hand of the operator isoccupied, as by holding the switch handle in open position, a spring,which is shiftable between different anchoring points, is providedbetween the latch 30 and bracket 20. In the embodiment illustrated, oneend of a coiled compression spring seats on a curved nub extending fromone edge of the top 23 of the bracket. The other end of the spring ismanually adjustable to seat on either of two seats on the latch 30 whichare at an obtuse angle to one another. When the spring is on the upperseat as in the top of Fig. 1, the latch is biased open and the doorkeeper 17 will clear the nose 32 when the door is swung to open it. Whenthe spring is on the lower seat as in the bottom of Fig. l, the latch isbiased toward closed position. With that bias, the latch willautomatically snap closed when the door is swung to closed position. Oneither seat the spring force acts to hold the bearing 31 of the latch 30against the bearing slot 24 of bracket 20.

if both latches have their springs seated on their upper seats, thelatches will be biased open and the door can be swung open when thehandle is in the proper position.

If one latch has its spring on its upper seat, the door can be swungopen when the handle is in the proper position provided the other latchis held open by the free hand of the operator.

If both latches are on their lower seats, the door will automaticallylatch itself shut when swung into closed position. For one person toopen the door, it will then become necessary to shift one or bothsprings to their upper seats. When that is done, the latch whose springis shifted will be biased toward open position. If the screw bolts weretightened, unscrewing them will permit any latch whose spring is on thebottom seat to move to open position.

Many switch boxes are provided with a rubber or flexible gasket 13 ontheir peripheral edge between the box and the cover. When the cover isshut, it is possible to press the cover against the gasket compressingit, to make a tighter seal. For that purpose, I preferably provide for asmall clearance C between the wings 26 and 35 of the bracket and latch,when the door is just closed. By tightening up on the screw bolt 19, theclearance can be reduced, causing compression of gasket as the covermoves slightly closer to the box. During such movement, the resilienceof the gasket, transmitted through the cover, maintains the keeper 17and latch nose 32 pressed tightly together. In order for such tighteningof the screw bolt to be accomplished to compress the gasket, there mustbe provision for lost motion in the pivotal mounting of the latch 30, asis possible in the pivot described and shown.

When a padlock is applied, the door will stay locked despite the removalof the screw bolts 19, because the loop of the padlock just fits in thehole 27 in the bracket and it cannot move out of the larger part of thekeyhole slot 37 in the latch 30. Hence the latch cannot pivot from thelatching position (lower part of Fig. l) to the unlatched position(shown in upper part Fig. 1) while the padlock loop is in said holes.

From the foregoing, it will be apparent that the new latch isparticularly useful when applied in pairs to a door which cannot besatisfactorily latched and secured with one latch and when one hand ofthe operator is otherwise occupied and not available to release one ofthe two latches. The latch is also useful individually or in pairs inany case where there is need to disable the latch temporarily but inwhich the latch will be moved to latching position when a screw bolt istightened, or a padlock is applied, or other means is provided to securethe door or cover permanently closed.

Modifications within the scope of my invention will occur to thoseskilled in the art. Therefore it is not limited to the specific formillustrated and described.

' What I claim is:

1. A box having a hinged cover, dual latching means positioned in spacedrelation on the box and cover a distance preventing their simultaneousoperation by one hand, each latching means comprising a bracket member,a pivoted latching member mounted on said bracket member, spring biasingmeans engaging said bracket and latching means, spaced seats for saidspring means between which said spring means may be manually shifted tochange the position into which said latching member is biased, meansengaged by said latching member when the cover is shut to hold it shutwhen said spring is on one seat but not engaged when said spring is onthe other seat, whereby on location of the spring of one latching meanson said one seat for biasing that latching member into non-latchingposition the other latch may be manipulated to release the door with onehand.

2. A box having a hinged cover, dual latching means positioned in spacedrelation on the box and cover a distance preventing their simultaneousoperation by one hand, at least one of said latching means comprising abracket member, a pivoted latching member mounted on said bracketmember, spring biasing means engaging said bracket and latching means,spaced seats for said spring means between which said spring means maybe manually shifted to change the position into which said latchingmember is biased, means engaged by said latching member when the coveris shut to hold it shut when said spring is on one seat but not engagedwhen said spring is on the other seat, whereby on location of the springon the seat which biases the latching member in non-latching positionthe other latching means may be manipulated to release the door with onehand.

3. A box having a hinged cover, spaced latching means for holding saidcover and box closed at spaced points, said latching means being spaceda distance preventing simultaneous manipulation by one hand, biasingmeans for at least one of said latching means, and means accommodatingsaid biasing means in either of two positions enabling said latchingmeans to be biased in either latching or non-latching position, saidbiasing means being shiftable by hand without tools between saidpositions whereby on location of the biasing means in the position whichbiases the latching means in non-latching position the other latchingmeans may be manipulated to release the door with one hand.

4. The combination for latching a cover to a box comprising a bracketmember having a mounting portion, a bearing portion bent at right anglesto said mounting portion and provided with a bearing recess and alsohaving a securing wing at right angles to the plane of said mountingportion and said bearing portion, a latching member having a bearingportion engaging said bracket member in its bearing recess, a latch noseadapted to engage means on said bracket member when in latching positionto hold the cover and box closed, and a securing wing bent at rightangles to the plane of said bearing and nose portions, and adapted to beparallel and to cooperate with said bracket wing, a bolt threaded intosaid bracket and engageable with said latch wing to hold said latchmember in latching position and connected to said bracket, a biasingspring between said bracket and latching'members shiftable manuallybetween two seats to vary the direction of bias for biasing the latchingmember toward a latching or a non-latching position.

5. The combination for latching a cover to a box consisting of a stampedsheet metal latch member adapted to engage a keeper to hold the box andcover shut, a stamped sheet metal bracket member on which said latch ismounted, a spring between said latch and bracket members, a plurality ofanchoring points on said members for said spring between which saidspring is manually shiftable to vary the direction of bias of said latchmember between a latching and a non-latching position.

6. The combination of claim 5 wherein the latching member and bracketmember are each provided with wings adapted to lie parallel, one of saidmembers being apertured and the other being tapped to receive a screwbolt, whereby the latch may be secured in latching position.

7. The combination of claim 5 wherein the latching member and bracketare each provided with wings, one being apertured and the other beingtapped, and a screw bolt entering said tap through said aperture andacting on said latch to move it into latching position when desired andto secure it there.

8. The combination for latching a cover to a box comprising a stampedsheet metal latch member having a bearing portion, a latch portionadapted to engage a keeper, and a wing portion, a bracket having aportion interengaged by said bearing portion and pivotally supportingsaid latch member, said bracket also having a mounting portion forattachment to a box and a wing portion to cooperate with the latch wingportion, said wing portions extending laterally from said mounting andlatch portions, and a spring between said latch and bracket members, aplurality of anchoring points on said members for said spring betweenwhich said spring is manually shiftable to vary the direction of bias ofsaid latch member between a latching and a non-latching position.

9. A device for latching a cover to a box in which the device ismountable on the one and a keeper is mountable on the other, comprisinga stamped sheet metal latch member having a bearing portion, a. latchportion adapted to engage a keeper, and a wing portion perpendicular tosaid .bearing and latch portions, a bracket having a portioninterengaged by said bearing portion and pivotally support ing saidlatch member, said bracket also having a mounting portion for attachmentto a box and a wing portion to cooperate with the latch wing portion,said wing portions being perpendicular to said mounting and latchportions, one wing portion being apertured and the other being tapped,and a screw bolt entering said tap through said aperture and acting onsaid latch to move it into latching position when desired and to secureit there, a spring between said latch and bracket members, a pluralityof anchoring points on said members for said spring between which saidspring is manually shiftable to vary the direction of bias of said latchmember between a latching and a non-latching position.

10. The combination as claimed in claim 5 in which.

the bracket member has an open bearing, and the latch member has an openbearing engaging the bearing recess of the bracket member, said springurging said latch and bracket members into engagement regardless whichseat said spring is on.

11. The combination as claimed in claim 5 wherein said latch and bracketmembers have a loose pivotal connection, and said spring urges saidlatch and bracket members into engagement regardless which seat saidspring is upon.

12. The combination as claimed in claim 8 wherein the wingportions arepierced to receive a padlock, the loop of said padlock preventing thelatch from moving relative to said bracket from latching position,thereby maintaining said cover and box locked.

13. The combination for latching two parts together comprising a keeperadapted to be mounted on one member and a latching device adapted to bemounted on the other, said latching device comprising a stamped'sheetmetal latch member having a bearing portion, a latch portion and alaterally extending wing portion, a bracket having a portioninterengaged by said bearing portion and pivotally supporting said latchmember, said bracket also having a mounting portion attached to one ofsaid two parts and a laterally extending wing portion to coopcrate withthe latch wing portion, a spring between said latch and bracket members,a plurality of seats on said members for said spring between which saidspring is manually shiftable to vary the direction of bias of said latchmember between a latching and non-latching position, said wing portionshaving clearance in latched position, and a bolt engaging said wings toreduce said clearance and move said parts more closely together byexerting pressure through said latch member on said keeper as said boltis tightened.

References Cited in the file of this patent UNITED STATES PATENTS1,002,259 Goedeke Sept. 5, 1911 1,885,713 Hammerly Nov. 1, 19322,121,620 Workman June 21, 1938 2,551,913 Toby May 8, 1951

